The diodes-based undoped and boron (B) doped ZnO films deposited onto p-Si by sol-gel method using spin coating technique were fabricated. The morphological properties of ZnO films were analyzed by field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM) measurements. The results indicated that the surface morphology of the films was affected by the boron incorporation. The diode parameters were determined from the analysis of the measured dark current-voltage curves. The ideality factor of the diodes is higher than unity and was found to be 2.53, 2.36 and 2.17 for the undoped, 0.1% B-doped and 0.3% B-doped ZnO diodes, respectively. The obtained diode parameters like barrier height and ideality factor suggest that B dopant improves rectifying properties of the ZnO diode. The interface states density (Dit) of the diode was determined by conductance-voltage method and Dit values for the undoped, 0.1% B-doped and 0.3% B-doped ZnO diodes were found to be 8.26 × 1011 eV−1 cm−2, 9.75 × 1011 eV−1 cm−2 and 6.61 × 1011 eV−1 cm−2, respectively. The obtained results indicate that the rectifying properties of the diodes-based nanostructure B-doped ZnO can be controlled by boron dopant.

The dielectric relaxation and AC conductivity of InP:S single crystal were studied in the frequency range from 100 to 5.25 × 105 Hz and in the temperature range from 296 to 455 K. The dependence of the dielectric constant (ε1) and the dielectric loss (ε2) on both frequency and temperature was investigated. Since no peak was observed on the dielectric loss, we used a method based on the electric modulus to evaluate the activation energy of the dielectric relaxation. Scaling of the electric modulus spectra showed that the charge transport dynamics is independent of temperature. The AC conductivity (σAC) was found to obey the power law: Aωs. Analysis of the AC conductivity data and the frequency exponent showed that the correlated barrier hopping (CBH) model is the dominant mechanism for the AC conduction. The variation of AC conductivity with temperature at different frequencies showed that σAC is a thermally activated process.

The ternary alloys and superlattices (SLs) of cubic rock-salt ScN and YN nitrides have been investigated using the first-principle full potential linear muffin-tin orbital (FPLMTO) method based on local-density approximation (LDA) and generalized gradient approximation (GGA96). The structural parameters as well as the electronic structures of these systems have been calculated and in the light of them, fundamental direct band gaps are expected, instead of the fact that ScN and YN are indirect band gap semiconductors.

In a recent work we calculated some electronic properties of metal-free phthalocyanine such as band structure, density of states and energy gap. We have also presented some optical properties such as dielectric function, electrical loss function, optical conduction, absorption and refractive index, some of which have never been studied before. Calculations were performed in the framework of density functional theory (DFT), using the full-potential linearized augmented plane wave (FP-LAPW) method. This study presents the electrical gap energy of metal-free phthalocyanine to be Eg = 2.4 eV which is in good agreement with experimental data. A trap energy level is also observed. Optical band gap is about 2.48 eV with an optical trap level at 1.48 eV. In addition, we obtained the static refractive index in the x-, y- and z-directions as n0xx = 2.43, n0yy = 2.06 and n0zz = 2.32. Finally, absorption spectra display the existence of strong absorption bands at the wavelengths of 400 and 800 nm which compare favorably with experimental results.

Amorphous zinc oxide (a-ZnO) thin films were synthesized from RF sputtered Zn thin films. The conversion was performed by processing Zn thin film in ultra high pure water at 95°C in various process times (120–180 min). X-ray spectra revealed the presence of amorphous ZnO in the processed films. The calculated band gap was laid in between 3.25 and 3.2 eV. Non-linear behavior in I-V characteristics was observed for all films. The structural defects of a-ZnO were confirmed with PL and Raman studies. The synthesized films at 180 min were more oxygen deficient.

Zinc oxide nanowires were synthesized by a simple chemical method using zinc acetate dihydrate, polyvinylpyrrolidone (PVP) and DI water as precursor, capping and solvent, respectively. Aluminum-doped ZnO nanowires were also synthesized by adding AlCl3 during the growth process. Both types of nanowires were used to fabricate a novel field ionization based gas sensor. The high sensitivity in low pressures, low working voltages, very low recovery time and good selectivity are the main advantages of these fabricated sensors. Electrical characteristics of the fabricated sensors were investigated while being exposed to several gases. Scanning electron microscopy (SEM) was used to analyze the nanowires structures.

An oxygen plasma treatment was used to prepare Fe-doped TiO2 nanoparticles. The anatase and rutile phases of TiO2 nanoparticles were achieved by an atmospheric pressure chemical vapor deposition method. The nanostructures were doped by Fe atoms to obtain a ferromagnetic nanostructure based on TiO2 nanoparticles. Atomic force microscopy and magnetic force microscopy were used for morphological and magnetic investigation of as-prepared samples. Measurements have confirmed the induced magnetic moment of the structures. Magnetic field-induced wettability of the prepared nanostructures was investigated in dark and under UV and visible light. The results showed a considerable enhancement in the wettability of the structure by applying the magnetic field.

A novel composite is fabricated through hybridizing graphene with polypyrrole (PPY) nanotube and manganese dioxide (MnO2) nanotube to comprehensively utilize the electrical double layer capacitance and pseudo-capacitance. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy are employed to characterize its structure. The SEM and TEM images illustrate that graphene/PPY nanotube/MnO2 nanotube composite (GPM) presents interconnected structure. The result of Raman analysis demonstrates the intimate interactions among PPY, graphene and MnO2. In addition, cyclic voltammetry (CV), galvanostatic charge-discharge and electrochemical impedance spectroscopy (EIS) techniques are used to measure the electrochemical properties. It is revealed that GPM presents excellent high-rate performance and its capacitance is as high as 469.5 Fg−1 at a current density of 0.3 Ag−1, higher than that of PPY and chemically reduced graphene sheet as well as the materials reported in the literature. Furthermore, long-term charge-discharge cycle test confirms that the fabrication of GPM can effectively merge the merits of graphene, PPY and MnO2. Additionally, EIS analysis illustrates that the presence of conductive graphene as well as the intimate interactions among graphene, PPY and MnO2 lead to the good electrochemical stability.

Effects of admixing argon to air DB discharge, at atmospheric pressure, on the electrical and optical emission characteristics have been studied. Optical emission spectroscopy is used to investigate the effect of argon admixing on the emission intensity of the nitrogen second positive systems (300–450 nm) and its relative population of N2(C3Πu,v′) state. Also the vibrational temperature of the nitrogen second positive systems has been calculated for the sequence Δv = −2, that follows Boltzmann’s distribution. It was found that the vibrational temperature of second positive system can be raised significantly from 0.31 to 0.35 eV in air dielectric barrier discharge (DBD) plasma at discharge current 0.5 mA with admixing of Ar gas at flow rate of 3 L/min. Admixing of argon to air DB discharge also enhances the discharge current, the electron density and the consumed power. Mechanisms of excitation and ionization processes of nitrogen molecules in this mixture have been studied. Processes which are responsible for the enhancement of the population density of N2(C3Πu,v′) and its vibrational temperature have been reported.

Optical emission spectroscopy and double Langmuir probe measurements are performed on a magnesium plasma from an inductively coupled plasma source. These measurements are performed in order to examine their feasibility to characterize the plasma, its degree of ionization and its deviation from thermal equilibrium.

To investigate the effect of thermal boundary resistance (TBR) on thermoelectric transport, the discontinuity in temperature is considered at the interface through Kapitza’s definition. The effect depends on two factors: the length of thermoelectric element and the value of TBR. More importantly, it is found that TBR has dramatic impact on the reduction in thermoelectric conversion efficiency, which decays exponentially with increasing TBR. The ratio of thermal boundary resistance to the length of thermoelectric element leading to the decrease of effective Seebeck coefficient largely accounts for the degradation of thermoelectric performance at the micro-scale.

This paper proposes an innovative, generally applicable numerical model for the calculation of the three-dimensional (3D) electromagnetic field generated by high voltage (HV) overhead power transmission lines (OHL) on the buried metallic structures (e.g., pipeline networks). The numerical analysis is based on a coupled finite element-boundary element model (FEM-BEM) designed to calculate the induced potential on buried pipelines for complex geometrical structures of HV OHL networks working on normal or fault conditions. The one-dimensional (1D) FEM technique based on pipe elements is used to discretize the mathematical model that describes the interior of the pipe and is coupled with the mathematical model that describes the exterior of the pipe using 3D-BEM integral equations. The full electromagnetic field model gives the flexibility to calculate the potential distribution in any point of the soil, providing useful information for the step and touching voltages. The computation accuracy of the numerical algorithm implemented is verified through two test problems by comparing the numerical results with those obtained using a software package based on the Transmission Line Method (TLM) and CIGRE formulae. Last part of the paper presents calculations of the induced potential on buried pipeline in the vicinity of a complex HV OHL working on normal and fault condition. The influence of the currents’ direction and magnitude flowing on the HV OHL on the induced pipeline potential distribution is analyzed.

This contribution presents an electro-hydrodynamic method for establishing the relationship between the motion of a polyelectrolyte through a solid-state nanopore and the surface-charge density of the nanopore. For a polyelectrolyte driven by an external electric field, our numerical calculations show that the dynamics of polyelectrolyte translocation through a nanopore are mediated by the charge density σ of the nanopore surface. The result implies that the charge density can be an effective way to regulate the polyelectrolyte translocation. Moreover, for the first time results indicate that a threaded polyelectrolyte may be retracted from a nanopore, and that a nanometer-scale channel can act as nanopore tweezers, in the same way as optical or magnetic tweezers allow manipulation of single molecules.